The present invention relates to a method of manufacturing a semiconductor device. For example, the method is usable in manufacturing a semiconductor device having a nonvolatile memory.
Electrically erasable and programmable read only memory (EEPROM) is widely used as a nonvolatile semiconductor storage device that is electrically writable and erasable. Such a storage device, which is typified by flash memory being currently widely used, has a conductive floating gate electrode enclosed by an oxide film or a trapping insulating film under a gate electrode of a metal insulator semiconductor field effect transistor (MISFET). In the storage device, a charge storage state in the floating gate or the trapping insulating film is used as memory information and read as the threshold of a transistor.
Recently, it is examined that a memory cell having a metal oxide nitride oxide semiconductor (MONOS) structure is used as the nonvolatile memory. Japanese Unexamined Patent Application Publication No. 2011-96772 describes that a defect formed at an interface between a gate insulating film and a substrate is repaired through heat treatment (hydrogen anneal) in a hydrogen atmosphere.